Vanguard is a close second in this competition. State Street, which got the ETF industry going with its SPDR S&P 500 fund, is in fifth place. BlackRock, whose iShares family is the biggest collection of ETFs, is in sixth place.

My definition of “best” is simple: It means “cheapest.” The whole point of ETFs—or, at any rate, of the indexed ones, which account for the bulk of assets—is to save money on portfolio costs.

All four of these ETF vendors have at least several very good deals for savers looking to keep their money management costs down. They all have a big presence on the Forbes Best ETFs list, a directory of funds that charge no more than 0.4% annually.

What sets Schwab apart is the consistency of its cost cutting. It’s hard to find any Schwab fund that is not a terrific buy. In that sense Schwab is the best of the best.

Here’s a summary of where ETF vendors appear on the Best ETFs list, ranked by how close a vendor tends to be to the top of a fund category in cost efficiency:

If you’re a cost-conscious investor, Vanguard is a fine place to park your money. But Schwab often edges Vanguard out. Schwab’s short-term Treasury fund undercuts Vanguard on price, as do its Treasury Inflation-Protected Securities, real estate and small-company stock funds.

BlackRock presents a more complicated picture. In some categories, such as the one for funds that cover most or all of the U.S. stock market, it has the very best deal. (Great buy: iShares Core S&P Total U.S. Stock Market, ITOT.) But there are also some mediocre offerings in the giant iShares catalog. That sinks the average iShares ranking down to the 45th percentile from the top.

To create the rankings for the Forbes Best ETFs survey we divided the universe of 737 eligible funds into 55 categories. There are, for example, 15 categories of sector funds (real estate and technology are two of the 15), six categories for different kinds of funds owning taxable high-quality bonds and six categories of international portfolios. Within each category there’s a cost ranking from cheapest to dearest. In almost every category where it has a contestant, Schwab has a fund at or near the top.

On average, the ranking of Schwab’s 22 entrants on the Best ETFs list is at the 20th percentile down from the top. That’s a strong showing given that a category may have only a dozen funds in it. This discount broker seems to be using its funds as a loss leader, to the immense benefit of penny-pinching investors.

The cheapest Schwab ETF is Schwab U.S. Small-Cap (SCHA), with a ten-year cost of ownership, per $10,000 invested, of -$61. Negative cost? The fund delivers that by more than fully offsetting its expense ratio with revenue from lending shares to short-sellers.

Vanguard’s 74 funds are on average 25 percentage points down from the the top. Cheapest: Vanguard FTSE All-World ex-U.S. Small Cap (VSS), with a ten-year cost of -$223.

Vanguard has $874 billion of Best ETF assets and Schwab $108 billion. They are both stealing business from costly fund operators.

DWS, the money management arm of Deutsche Bank, has earned itself a third-place slot on the ranking of ETF families with its bargain-priced Xtrackers funds. Goldman Sachs has some attractive offers, too. Its ActiveBeta U.S. Large-Cap Equity (GSLC) is cheapest in the multifactor category.

In the cellar: Pimco and Oppenheimer, with rankings averaging below the 80th percentile. Their funds aren’t horribly expensive—that description belongs to products that don’t even qualify to be mentioned in the Best ETFs survey—but they are a long ways from being terrific bargains.

Sixty-four Best ETFs appear on our Honor Roll. These are funds that are at or near the top of their categories in cost efficiency and also get honor grades for liquidity. Schwab stands out here, with more than half of its funds on the Honor Roll. Vanguard and BlackRock’s iShares suite each claim 17 Honor Roll members.

The table of percentiles covers only families with at least three funds listed in Best ETFs. Among operators shy of the three-fund minimum, one stands out: GraniteShares. This upstart has two Best ETFs funds and an average position at the 12.5th percentile.

GraniteShares is a small operation, but its price-chopping entrance into the commodity fund business is drawing attention. GraniteShares Gold Trust (BAR) costs 0.2% annually, half the fee of the market-leading SPDR Gold Trust (GLD). BAR is gaining assets rapidly. It had $14 million at the May cutoff date for the Best ETFs list, but within two months zoomed to $258 million.